The present invention relates to a method for manufacturing a liquid crystal display device which is used in an optical display, and more particularly to a method for forming an insulation layer to partition liquid crystal layers in a liquid crystal display having a multi-layer liquid crystal structure.
Currently utilized liquid crystal display devices, of an active matrix type use a simple X-Y matrix or thin film transistor (TFT) driving method. Both driving methods use a twisted nematic (TN) type or super twisted nematic (STN) type liquid crystal and a polarizing plate for controlling light. However, the polarizing plate in the liquid crystal display (LCD) intercepts more than 50% of the light. Accordingly, efficiency is lowered. For this reason, a background light source having a considerable intensity is required to obtain a picture image having a desired brightness. Thus, in a laptop word processors or computers which use a dry cell battery or an accumulative battery cell as a power supply source extended use is limited due to the excessive power consumption of the light source.
Also, in known LCDs, including the TN and STN LCD devices, since the liquid crystal is charged between two glass plates, a cell gap must be made within stringent range requirements to form a uniform picture image. Therefore, due to current technological limitations in the manufacturing of glass plates, enlarging LCD panels is hard to achieve.
Taking the above-described problems into consideration, in order to decrease the need for very precise cell gap adjustment, it has been known to eliminate the polarized plate to increase efficiency and instead use a single sheet of a base plate. Examples of LCD without a polarized plate include a cholesteric nematic transition (CNT) type which uses a phase transition effect and a dynamic scattering mode (DSM) type which was devised early in LCD development. The DSM type LCD exhibits slow response time and cannot be made thin. For those reasons it is no longer in common use.
Another example of an LCD not using a polarized plate to increase the efficiency of light is a polymer-dispersed liquid crystal display (PDLCD). However, since the PDLCD is made of a polymer material, more than half of whose volume is light-transmitting, the scattering of light is needed to obtain a clear contrast ratio. To attain these requirements, there is structural limitation that the thickness of the liquid crystal layer should be at least 20 m.
An LCD which adopts an electrical field effect type liquid crystal having a new structure in which the above conventional problems of the LCD are considerably improved, has been developed by a co-inventor, Nobuyuki Yamamura, and which bears U.S. patent application Ser. No. 08/058,712, was filed on May 10, 1993, and is expressly incorporated by reference herein. Improved LCD's have also been developed, which are described in Korean patent applications Nos. 15191, 15192, 15193 and 15194 filed in 1992.